Smoke producers

ABSTRACT

A smoke producer comprising a smoke box, having a smoke outlet at its upper regions, a grate within the smoke box and a rake mechanism capable of being reciprocated to rake fuel, such as sawdust or peat, burning on the grate. The producer includes a feed hopper and fuel dispensing means by which fuel is fed to the grate in a controlled manner and the air supply to the smoke box is controlled to obtain optimum smoke production.

United States Patent 1191 Snelling [111 3,809,056 1451 May 7,1974

[ SMOKE PRODUCERS [76] Inventor: Aubrey Francis Snelling, White House, Kemp Rd., Swanland, North Ferriby, East Yorkshire, England [22] Filed: Jan. 10, 1972 [21] Appl. No.: 216,733

[30] Foreign Application Priority Data Jan. 12, 1971 Great Britain 1353/71 [52] U.S. Cl 126/595, 99/476, 99/482, 110/38 [51] Int. Cl A23b 1/04 [58] Field of Search 126/595, 174, 173; 99/473, 474, 475; 110/38, 37, 7 A, 114

[56] References Cited UNITED STATES PATENTS 1,548,550 8/1925 Pfleiderer .l 126/173 2,515,455 7/1950 Lipton 126/595 2,858,212 10/1958 Durant et al 214/35 A 2,011,344 8/1935 Kelly 110/38 FOREIGN PATENTS OR APPLICATIONS 257,960 7/1927 Great Britain 110/38 Primary Examiner-William E. Wayner Assistant Examiner-William E. Tapolcai, Jr. Attorney, Agent, or Firm-Diller, Brown, Ramik & Wight [5 7] ABSTRACT A smoke producer comprising a smoke box, having a smoke outlet at its upper regions, a grate within the smoke box and a rake mechanism capable of being reciprocated to rake fuel, such as sawdust or peat, burning on the grate. The producer includes a feed hopper and fuel dispensing means by which fuel is fed to the grate in a controlled manner and the air supply to the smoke box is controlled to obtain optimum smoke production.

18 Claims, 5 Drawing Figures PATENTED MY 7 I974 SHEET 1 BF 3 slaosloss PATENTEDHAY 7 I974 SHEET 3 BF 3 SMOKE PRODUCERS The present invention relates to smoke producers for use in the curing of fish, meats, cheese and the like food stuffs.

Smoke producers are known and generally comprise a sheet iron smoke box within which sawdust is burned and the smoke produced by the burning sawdust is allowed to rise up the smoke box to a smoke outlet in the upper regions thereof. The smoke producer is located outside a smoke treatment room or kiln, and the smoke from the smoke outlet is ducted to the kiln.

According to the present invention a smoke producer comprises a smoke box having a smoke outlet at its upper regions, a grate within the smoke box, a rake mechanism capable of being reciprocated to rake fuel on said grate and a fuel dispensing means for delivering fuelto the grate at a desired measured rate.

Preferably the fuel dispensing means includes a fuel hopper, a duct connecting the hopper with the fuel delivery end of the grate and a fuel dispensing device in said duct for controlling the supply of fuel from the hopper to the grate. Y

The fuel dispensing means may comprise a rotary valve or a worm feed and, conveniently, the fuel dispensing means may be driven through a ratchet and pinion arrangement, with an associated lost motion device by which the rate of fuel delivery can be varied.

In one embodiment of the invention a water spray is provided for damping the fuel in the hopper.

The fuel dispensing means preferably delivers the fuel to a dead plate adjacent the fuel delivery end of the grate and the fuel is raked from the dead plate and over the grate by the reciprocating rake.

The rake preferably comprises spaced longitudinal members supporting spaced transverse fuel engaging members and said rake may conveniently be reciprocated by a crank arranged for rotation at constant speed to impart a circular motion to one end of the rake whilst the other end of the rake slides on a substantially fixed part of the smoke producer.

Alternatively the rake is connected through a connecting rod to an eccentric, arranged for rotation of constant speed to effect reciprocation of the rake, and the rake includes cam members, engageable with cam tracks on or adjacent the grate, which allows the rake to adopt a low position relative to the grate in a forward fuel advancing stroke of the rake and which lift the rake to a high position relative to the grate for the return stroke.

The invention will now be described further by way of example with reference to the single figure accompanying the provisional specification and the accompanying drawings, in which:

FIG. 1 shows a vertical section through a smoke producer in accordance with the invention;

FIG. 2 shows a vertical section through a second embodiment of the invention;

FIG. 3 shows a detail side view of the rake lifting arrangement when the rake is advancing to displace fuel over the grate;

FIG. 4 shows a detail side view of the rake lifting mechanism of FIG. 3 when the rake is returning; and

FIG. 5 shows a detail side view, partially in section, of the fuel measuring and dispensing device for the embodiment shown in FIG. 2.

The smoke producer comprises a main frame 11 supporting a sheet iron smoke box 12 in which sawdust is burned on a perforated grate l3 and the smoke from the burning sawdust rises up the box 12 to a smoke outlet 14 in the upper region of the box 12. The sawdust is supplied to grate 13 from a hopper 15 which discharges sawdust through a rotary valve 16 onto a dead plate 17 at one end of the perforated grate 13. The sawdust is displaced from dead plate 17 on to and over the perforated grate 13 by a reciprocating rake 18 and the ash from the burnt sawdust falls off the cold end of the perforated grate 13 into an ash box 19.

An electric motor 20 drives a reduction gear box 21 through endless bands 22 and reduction gear box 21 drives a combustion fan 23 which blows air into the space between the bottom of the smoke box 12 and the perforated grate 13 to provide combustion air for the burning sawdust.

The air delivered to the smoke box 12 by fan 23 is carefully controlledto ensure a continuous supply of smoke of the desired quality for efficient smoking.

Reduction gear box 21 also drives a water pump 24 which supplies water to feed ducts25 in hopper 15 whereby a metered volume of water is released into the hopper 15 to damp the sawdust therein.

The water cooled box 26 extends across the width of smoke box 12 and has one end located above but close to the cold end of the perforated grate 13. The box 26 extends from the cold end upwardly at an angle of approximately 20 for about one half of the length of grate 13, and the box 26 forms part of a closed water circulation system including a cooler (not shown).

The reciprocating rake 18 comprises side members 27 (only one of which is shown in the drawing) supporting a plurality of transverse scrapers 28. At the driving end of rake 18, that end remote from the perforated grate 13, the side member 27 illustrated is pivotally connected to a link 29 and member 27 includes a bracket 30 engageable with the top of link 29 to prevent anticlockwise angular displacement of ling 29 relative to member 27 beyond the position in which the longitudinal axis of member 27 is parallel with the axis of link 29.

Link 29 is connected to an eccentric arm 31 mounted for rotation with a shaft 32 supported inbearings (not shown) attached to the machine frame 11 and shaft 32 is rotated by way of an endless band 33 from reduction gearbox 21. The axis of shaft 32 lies substantially inthe plane of the top of dead plate 17 and, as will be seen from the drawing, the plane of the top of dead plate 17 is above the plane of the perforated grate 13.

The side member 27 not illustrated is, in identical manner to the side member 27 illustrated, pivotally connected to a link 29 which is in turn pivotally connected to an eccentric arm 31 mounted on a shaft 32 rotated by the reduction box 21 through an endless band 33 and the link 29, and shaft 32, are so arranged that the members 37 are displaced simultaneously by the rake driving arrangements 29, 31, 32 and 33. The forward ends of members 27 rest on guides 34 which support the said forward ends of members 27 substantially in the plane of the dead plate 17.

With the above arrangement the rake 18 is lifted above dead plate 17 on the retraction stroke (as shown in full line in the drawing) and slides across the dead plate 17 on the forward stroke (as shown in broken line in the illustration). The discharge of sawdust from tracted position and thus the forward stroke of rake 18 causes the sawdust on the dead plate 17 and on the perforated grate 13 to be pushed forward whilst on the return stroke the rake 18 is lifted and thus the sawdust is not subjected to an excessive backward displacement over the grate or dead plate 17 and loss of sawdust from the rear edge of the dead plate 17 is avoided.

In operation sawdust dumped into hopper 15 is dampened by water flow from ducts and discharged through rotary feed valve 16 onto dead plate 17 whilst rake 18 is in a retracted position. The forward stroke of the rake 18 pushes the sawdust off the dead plate 17 onto the perforated grate 13 where the sawdust is initially warmed and then ignited as it is displaced over the grate 13 by successive strokes of the rake 18.

As the sawdust dries out there is a tendency to flaring, particularly after partial combustion has taken place, and such flaring is detrimental to both the volume and quality of the smoke produced. The water cooler 26, by absorbing heat from the cold half of the grate l3, cools the region of grate 13, where flaring is most likely, and thus the cooler 26 serves to reduce, and in many cases eliminate flaring.

The smoke released through the outlet is thus a cooled smoke and carry over of ash and sparks is substantially, if not entirely eliminated, by the presence of the cooler alone.

In the embodiment illustrated in FIG. 2 a smoke producer comprising a casing 40 has an opening 41 in its upper regions through which fuel, in this case peat, can be charged into a hopper 42. Fuel is discharged from hopper 42 through a hopper outlet duct 43 and falls onto a dead plate 44 before being raked over a movable grate plate 45. The movable grate plate 45 rests above a fixed grate 46 and ash from the burned fuel drops through grate plate 45 and fixed grate 46 into an ash box 47. l

The fuel in hopper 42 is continuously stirred by a paddle-wheel 48 mounted on a shaft 49 rotatably supported by the sidewalls of hopper 42 and shaft 49 is rotated through a pulley wheel 50 mounted thereon and an endless band 51 which passes over pulley wheel 50 and a pulley wheel 52 on a main drive shaft 53, The main drive shaft 53 is rotated at constant speed by an electric motor 54 through a pulley wheel 55, on the output shaft 56 of motor 54, an endless band 57, and

a pulley 58 on drive shaft 53.

A pulley wheel 59 on the shaft 49 drives a pulley wheel 60 on a shaft 61 through an endless band 62 and an eccentric pin 63 on pulley wheel 60 is rotatably engaged in one end of a connecting rod 64 and the other end of connecting rod 64 is pivotally connected to a cross head 65 attached to a push rod 66 and push rod 66 is, in turn attached to the movable grate plate 45. The cross-head 65 has two parallel pins 67 and 68 extending therefrom and slidably engaged in an end wall 69 of dead plate 44. Two coil springs 70 and 71, mounted on pins 67 and 68 respectively lead cross head 65 towards the left as seen in FIG. 2.

The main drive shaft 53 has a cranked portion 530 and a rake reciprocating connecting rod 72 is rotatably attached at one end to cranked portion 53. The other end of connecting rod .72 is pivotally connected to a rake, comprising longitudinal side rails 73 with transverse fuel displacing rails 74.

The end of the rake remote from connecting rod 72 is supported by cam tracks 75 engageable by carn members 76, cam members 76 are mounted for limited angular displacement on a rail 74 and, during a forward diplacement movement of the rake (towards the right as viewed in FIG. 2), the cam members pivot to lie with their longitudinal axes substantially horizontal, whereby the rake is in a low position relative to the grate, and in a return displacement stroke the cam members 76 lie with their longitudinal axes vertical so that they ride along their respective cam tracks 75 with the rake end supported in a high position relative to the grate.

The hopper outlet duct 43 contains a fuel measuring and dispensing device comprising a feed worm 77 mounted on a shaft 78 and rotated by a pawl 79 engaged with a ratchet wheel 80 on shaft 78. The pawl 78 is pivotally mounted on an arm 81, rotatably supported on shaft 78, and the free end of arm 81, is connected to an eccentric pin 82 on pulley 58 by a connecting rod 83. A stop pawl 84 pivotally supported by duct 43, engages ratchet wheel 80 to prevent rotation of the feed worm 77 in the direction opposite to the rotation imparted by the pawl 79 and pawls 78 and 84 are resiliently loaded against ratchet wheel 80 by springs 78a and 84a respectively.

The connecting rod 83 is rotatably mounted on pin 82 and rotatably supported on the free end of arm 81 by a pin 85, secured to arm 81 and rotatable in a slot 86 in connecting rod 83. A sliding block 87 in slot 86 is loaded by a coil compression spring 88 to urge pin towards the right hand side of the slot 86 as seen in FIG. 2. A stop plate 89 mounted on the inner end of a control rod 90 can, by suitably positioning contral rod 90, engage with the pin 85.

A smoke outlet 91 is provided in the roof of casing 40 and a fan 92 is provided for supplying combustion air to the fuel.

The smoke producer shown in FIG. 2 operates as follows:

With electric motor 54 operating to rotate output shaft 56 endless band 57 rotates drive shaft 53 at constant speed, pulley 52 displaces endless band 51 to cause paddle wheel 48 to rotate, the cranked part 530 of shaft 53 acts through connecting rod 72 to reciprocate rake 73, 74, endless band 62 rotates shaft 61 to cause, through connecting rod 64, reciprocation of the movable grate plate 45, and pulley wheel '58 acts through connecting rod 83 to cause, through arm 81 and pawl 79, step by step rotation of ratchet wheel 80 and feed worm 77.

Fuel, in this case peat, charged into hopper 42 is stirred by paddle wheel 48 and discharged by the worm feed 77, to fall from duct 43 onto the dead plate 44. The angular displacement of arm 81, and thereby the rate of fuel delivery through duct 43, is manually controlled by displacing control rod 90 so that stop plate 89 engages and arrests the displacement of pin 85, and thereby arm 81, before the advance of connecting rod 83 is terminated. When stop plate 89 stops pin 85 the further advance of connecting rod 83 causes pin 85 to be displaced along slot 86 cause further compression of spring 88 and this tension is released during the initial part of the return stroke of connecting rod 83. Thus, by arresting the displacement pin 84 before the full delivery stroke of connecting rod 83 accurate control of the fuel feeding rate is obtained.

The fuel delivered from duct 43 onto dead plate 44 is pushed by transverse rails 74 of the rake off of the dead plate and onto the reciprocating grate plate 45 where the fuel is burned, being continuously distributed by the moving rake and agitated by the reciprocating moving grate 45. The ash from the burned fuel falls through moving grate 45 and fixed grate 46 into ash box 47 and periodically removed through access doors 47a in ash box 47 and doors 40a is casing 40.

As the fuel on moving grate 45 is being continuously stirred and disturbed by the rake and by the reciprocation of moving grate 45 the smoke from the burning fuel rises up the smoke box to the smoke outlet 91 and through suitable ducting to a smoking kiln or kilns, and a fan 92, provided to deliver air beneath dead plate 44, to assist combustion of the fuel, maintains the internal pressure within casing 40 above atmosphere thereby further assisting the release of smoke through outlet 91.

In the embodiment illustrated in FIG. 2 the main drive shaft 53 is rotated anticlockwise and it will be observed that cranked part 530 of shaft 53 is angularly in advance of eccentric pin 82 so that, in time, the stroke of connecting rod 72 is in advance of the stroke of connecting rod 83. Further, the release of fuel by the worm feed is arranged, by the disposition of the pawls 79 and 84, to take place when the arm 81 is being displaced clockwise by connecting rod 83 so that the delivery of fuel takes place whilst the rake is finishing the latter part of its return stroke and is starting its forward stroke whereby the fuel delivered onto dead plate 44 lies forward of fuel displacing rails 74 of the rake and is displaced on the forward stroke of the rake over the dead plate 44 and onto the moving grate 45.

FIGS. 3 and 4 illustrate in detail, the operation of the rake lifting arrangement and it will be appreciated from FIG. 3 that as the rake advances to displace fuel over the grate the cam members 76 are free to pivot to lie substantially horizontal so that the rake advances in a low position. As the rake nears the end of its forwards stroke each cam member 76 runs down the inclined track 750 of its respective cam track 75 and off the track whereupon it can rotate under gravity to adopt a substantially vertical position.

When the rake begins to return the upright cam members 76 engage the inclined sections 75a and friction between the tip of each cam member 76 and its respective track causes the cam member to engage a pin 94 protruding from the side rail 73 of the rake, the pin 94 prevents anti-clockwise rotation of the cam member 76 and thus the cam members are retained in an upright position, with the rake lifted to a high position, until the next forward displacement of the rake.

The rake may, as hereinbefore described, comprise straight transverse members extending between the longitudinal side members. Alternatively the transverse members can have other shapes and it has been found advantageous to have at least those transverse members above the dead plate, chevron" shaped, that is to say having their mid-regions forward of the sides.

Although the present invention has been described by way of examples it will be appreciated that many modifications and variations of the specific examples will be apparent to persons skilled in the art and such variations when used in the combinations defined in the following claims must lie within the scope of the invention.

I claim:

1. A smoke producer comprising a smoke box, a smoke outlet in the upper regions of said smoke box, a longitudinally extending grate within said smoke box, a reciprocating rake means for raking fuel onto and longitudinally along said grate and a fuel dispensing means for delivering fuel to the grate at a desired measured rate, means supporting said rake in spaced relation above said grate independently of said grate, and means for independently displacing said rake longitudinally of said grate and relative thereto.

2. A smoke producer in accordance with claim 1 wherein said fuel dispensing means comprises a fuel hopper, a duct connecting said fuel hopper with a fuel delivery end of said grate and a controlled fuel dispensing device in said duct.

3. A smoke producer in accordance with claim 2 wherein the fuel dispensing device comprises a rotary valve.

4. A smoke producer in accordance with claim 2 wherein the fuel dispensing device comprises a worm feed.

5. A smoke producer in accordance with claim 2 wherein the fuel hopper includes fuel stirring or agitating means.

6. A smoke producer in accordance with claim 2, wherein the fuel hopper includes water spray means for spraying fuel in the hopper with water.

7. A smoke producer in accordance with claim 2 wherein said fuel dispensing device is actuated by a ratchet and pinion arrangement driven through a lostmotion device whereby the rate of delivery of fuel through the device can be varied.

8. A smoke producer in accordance with claim 1 wherein the fuel dispensing means delivers fuel to a dead plate adjacent the fuel delivery end of the grate and fuel delivered to said dead plate is raked from the dead plate and over the grate by the rciprocating rake.

9. A smoke producer in accordance with claim 1 wherein the rake comprises spaced longitudinal members supporting spaced transverse fuel engaging members.

10. A smoke producer in accordance with claim 9 wherein the means for displacing the rake includes the rake being connected at one end to a crank arranged for rotation at constant speed to impart a circular motion to the one end of the rake while the other end of the rake slides on a substantially fixed part of the smoke producer.

11. A smoke producer in accordance with claim 9 wherein the means for displacing the rake includes one end of the rake being connected through a connecting rod to an eccentric arranged for rotation of constant speed to effect reciprocation of the rake, and the rake includes cam members engageable with cam tracks on or adjacent the grate, which allow the rake to adopt a low position relative to the grate in a forward fuel advancing stroke of the rake and which lift the rake to a high position relative to the grate for the return stroke.

12. A smoke producer in accordance with claim 1 wherein there are means for vibrating said grate.

13. A smoke producer in accordance with claim 1 wherein said grate comprises a static grate, a perforated grate above the static grate and means for vibrating the static grate.

14. A smoke producer in accordance with claim 1 and wherein a cooler is located above the grate in the smoke box to effect a cooling of products of combustion rising from the grate towards the smoke outlet 15. A smoke producer, in accordance with claim 14, and wherein said cooler is located above a downstream end of the grate and presents an inclined face up which products of combustion rising from combustion fuel on said downstream end of said rate are caused to flow.

16. A smoke producer in accordance with claim wherein said cooler is water cooled and provided with air blower. 1 

1. A smoke producer comprising a smoke box, a smoke outlet in the upper regions of said smoke box, a longitudinally extending grate within said smoke box, a reciprocating rake means for raking fuel onto and longitudinally along said grate and a fuel dispensing means for delivering fuel to the grate at a desired measured rate, means supporting said rake in spaced relation above said grate independently of said grate, and means for independently displacing said rake longitudinally of said grate and relative thereto.
 2. A smoke producer in accordance with claim 1 wherein said fuel dispensing means comprises a fuel hopper, a duct connecting said fuel hopper with a fuel delivery end of said grate and a controlled fuel dispensing device in said duct.
 3. A smoke producer in accordance with claim 2 wherein the fuel dispensing device comprises a rotary valve.
 4. A smoke producer in accordance with claim 2 wherein the fuel dispensing device comprises a worm feed.
 5. A smoke producer in accordance with claim 2 wherein the fuel hopper includes fuel stirring or agitating means.
 6. A smoke producer in accordance with claim 2, wherein the fuel hopper includes water spray means for spraying fuel in the hopper with water.
 7. A smoke producer in accordance with claim 2 wherein said fuel dispensing device is actuated by a ratchet and pinion arrangement driven through a lost-motion device whereby the rate of delivery of fuel through the device can be varied.
 8. A smoke producer in accordance with claim 1 wherein the fuel dispensing means delivers fuel to a dead plate adjacent the fuel delivery end of the grate and fuel delivered to said dead plate is raked from the dead plate and over the grate by the rciprocating rake.
 9. A smoke producer in accordance with claim 1 wherein the rake comprises spaced longitudinal members supporting spaced transverse fuel engaging members.
 10. A smoke producer in accordance with claim 9 wherein the means for displacing the rake includes the rake beIng connected at one end to a crank arranged for rotation at constant speed to impart a circular motion to the one end of the rake while the other end of the rake slides on a substantially fixed part of the smoke producer.
 11. A smoke producer in accordance with claim 9 wherein the means for displacing the rake includes one end of the rake being connected through a connecting rod to an eccentric arranged for rotation of constant speed to effect reciprocation of the rake, and the rake includes cam members engageable with cam tracks on or adjacent the grate, which allow the rake to adopt a low position relative to the grate in a forward fuel advancing stroke of the rake and which lift the rake to a high position relative to the grate for the return stroke.
 12. A smoke producer in accordance with claim 1 wherein there are means for vibrating said grate.
 13. A smoke producer in accordance with claim 1 wherein said grate comprises a static grate, a perforated grate above the static grate and means for vibrating the static grate.
 14. A smoke producer in accordance with claim 1 and wherein a cooler is located above the grate in the smoke box to effect a cooling of products of combustion rising from the grate towards the smoke outlet.
 15. A smoke producer, in accordance with claim 14, and wherein said cooler is located above a downstream end of the grate and presents an inclined face up which products of combustion rising from combustion fuel on said downstream end of said rate are caused to flow.
 16. A smoke producer in accordance with claim 15 wherein said cooler is water cooled and provided with water inlet and outlet connections.
 17. A smoke producer in accordance with claim 1 wherein air control means are provided for adjusting and controlling the flow of air into the smoke producer whereby to obtain the desired smoke production from the fuel.
 18. A smoke producer in accordance with claim 17 wherein said means for adjusting and controlling the flow of air through the smoke producer comprises an air blower. 